A solenoid is a coil of wire that provides a magnetic force when a current is passed through it. A solenoid can create controlled magnetic fields, and therefore, solenoids are often used as electromagnets to generate linear forces. Accordingly, a solenoid includes a fixed stator and a moving armature. Solenoids can be used in a variety of applications, such as in actively controlled couplings and differentials. In these types of applications, it is common to apply a known input to the solenoid to receive a predictable output force. However, one factor that affects the force output of a solenoid is the air gap present between the stator and the armature. For a solenoid used in an all-wheel drive (AWD) coupling, it has been difficult to measure or monitor the air gap directly. Therefore, is difficult to predict the input required to obtain desired outputs.